| Transmissible gastroenteritis(Transmissible gastroenteritis,TGE)is a transmissible gastroenteritis virus(Transmissible gastroenteritis virus of swine,TGEV)caused an acute,highly contagious disease,caused huge economic losses to the pig industry worldwide.At present,TGE is mainly based on vaccine immunization,but can not provide comprehensive protection.Antiviral effect of probiotics and their culture supernatant,intestinal mucosal cell injury has been confirmed;probiotic species currently known antiviral activity of many,but the species and strain differences.Many of the results showed that Chinese herbal medicine can improve the immune function of the body,with good anti-virus,anti-tumor,improve the survival rate of cells and so on.Among them,the effect of Astragalus Polysaccharides and letinous edodes Polysaccharides were significant,and they were widely studied and applied.The purpose of this study is through the combination of Astragalus extract,Letinous edodes extract,probiotics supernatant against TGEV infection and evaluation of probiotics supernatant were combined with two kinds of extracts Anti-TGEV effect,in order to provide new ideas for the prevention and treatment of TGE,and establish a theoretical foundation for the development of the new Chinese herbal medicine and probiotics composite products.This research mainly adopts MTT method,ELISA method,fluorescence quantitative PCR method,selection of astragalus extract and letinous edodes extract and culture of Bacillus subtilis,Food starch lactobacillus,Enterococcus faecium three probiotics supernatant and cells using PK-15 platform,with TGEV infected,respectively through detecting Virus inhibition rate,Virus content,expression of TGEV N gene and IFN-gamma m RNA,evaluate the antiviral effect of Letinous edodes and Astragalus extraction liquid,probiotics supernatant,their complex and other ingredients.The results showed that three kinds of probiotics culture supernatant had Anti-TGEV effect.In general,virus inhibition rates of culture supernatant was Bacillus subtilis>Enterococcus faecium>Food starch lactobacillus;virus treatment in the highest inhibition rate is processed at the same time with virus,followed by supernatant pretreatment,finally supernatant of postprocessing;inhibition of the virus supernatant overall dependent on concentration.This study found that Astragalus Extract,Letinous edodes extract,astragalus polysaccharides and letinous edodes polysaccharides have different levels of Anti-TGEV effect.Among them,the rate virus inhibition of Astragalus extract was better than that of Letinous edodes extract,and Astragalus polysaccharides was better than Letinous edodes polysaccharides,and the treatment method was pretreatment>co-processing>aftertreatment.The Anti-TGEV effect of the extract and the purified polysaccharide were also concentration dependent,and the inhibition rate was proportional to the concentration.Anti-TGEV effect of probiotics supernatant combined with extract are improved,the best one is Bacillus subtilis combined with Astragalus extract,and the optimal treatment method was co-processing,followed by pretreatment,and finally was postprocessing.The results showed that the Anti-TGEV effect of Bacillus subtilis combined with Astragalus extract was significant,and the content of TGEV in PK-15 cells could be reduced effectively by the combination in 32 hours.This study showed that Bacillus subtilis combined with Astragalus Polysaccharides combined can make can make the expression of TGEV of N gene on PK-15 cells decreased,IFN-? mRNA expression increased,while expression with time showed different trends.It was found that the E.coli lipopolysaccharide(LPS)could weaken the antiviral effect of the complex.In addition,this study also showed that porcine aminopeptidase receptor blocking agent Bestatin also has the effect of Anti-TGEV,the TGEV inhibition rate there was a dose-response effect,compared with virus inhibition rate of probiotics culture supernatant combind with extract,we found that although both virus inhibition rate with the decline in concentration decreased,but the change is not the same.Based on this we hypothesized that the probiotic culture supernatant and the extract the antiviral mechanism of the compound may not be the same as Bestatin.In summary,Astragalus extract and Letinous edodes extract were used in combination with three kinds of probiotics culture supernatant,which showed good enhancement effect.This study provides a reference for the prevention and treatment of TGE infection in piglets,and provides a theoretical basis for the combined use of traditional Chinese medicine and probiotics. |
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